Nearly two and a half years after the murder of their daughter, the parents of Brandy Renger have been barred from the courtroom in which her accused killer faces trial.

Kay Renger is expected to testify so she knew she wouldn't be allowed to listen to testimony. But Everett Renger was never supposed to be called as a witness, yet he is still banished from the courtroom and he was never really told why.

"I was very surprised and kind of a little pissed off," said Ruth Marin-Eason, head of the Heights chapter of the group Parents of Murdered Children.

Brandy Renger was just 39 when murdered July 2, 2014. Her body was found in the Katy-area apartment of her then 19-year-old boyfriend Jose Salas-Bustamante. She'd been stabbed to death. Salas-Bustamante told investigators he woke up to find her dead and had no idea what happened.

As trial began in the 182nd District Court, Judge Jeannine Barr invoked a rule commonly used in court which states those who are expected to testify cannot listen to testimony during trial. The rule is designed to keep testimony from being tainted by what someone else might say.

But how does that apply to someone who has not been subpoenaed to testify?

"That's a good question. We've yet to get an answer for that," said City of Houston Crime Victim advocate Andy Kahan.

In his 25 years fighting for victims, Kahan says he's never seen anything like this. A murder victim's father - barred from the courtroom without explanation.

"He just wants to be here. He's a grieving father who wants to be here to see the trial of the person allegedly murdered his daughter," Kahan said.

Kahan and prosecutors have asked the judge to reconsider, citing legal research from the National Crime Victim Law Institute which states victims can be excluded from court "only when the court determines that the victim's testimony would be 'materially affected' if the victim were to hear the testimony of other witnesses at trial."

Marin-Eason says this is proof of an inherent bias in the criminal justice system against victims and their families.

"They always give the criminal all these rights and the victim don't get any," she said.

Both the judge and the defense attorney in this case refused to respond to questions. Prosecutors have appealed the judge's ruling.